1. Field of the Invention
The invention relates to a flexible bag of a heat-sealable or heat-weldable plastic sheet material and adapted to receive liquid and/or pasty media, comprising two sidewall-forming flat elements sealingly connected to each other along their longitudinal edges and their lower transverse edge and forming a dispensing opening at their upper end.
2. Discussion of Prior Art
Such bags made of plastic sheet material are known in particular for use as disposable beverage packages e.g. from DE-U-88 07 593.1. Such packages usually terminate in a pointed end and have a filling volume of 0.2 litres. The sheet material employed for such beverage packages comprises a thick aluminum sheet layer serving among other purposes to stabilize the package. Such flexible bags are usually designed as stand-up bags. The bottom side is formed with a support bottom permitting the bag to be placed on a support after it has been opened without the risk of the bag's contents spilling from the dispensing opening or the bag toppling over. In beverage packages of this type the dispensing opening may for instance be determined by a pierceable, weakened portion capable of being pierced by a drinking straw terminating in a pointed end.
Aside from beverages, flexible bags are also used for filling them with liquid or pasty media, e.g. liquid detergents. Flexible bags of this type are mainly used as refill packages.
A basic advantage of the flexible bags can be seen in the fact that they can be folded extremely flat in their empty state so as to require very little space.
The filling of such flexible bags with liquid or pasty media is carried out in an automatic operation. For this purpose, the bag is placed upright with its dispensing opening pointing upwardly so as to permit a filling spout to be inserted thereinto. After the bag has been filled, the dispensing opening is closed by welding or sealing. During the fully automatic filling of the flexible bags at a high speed it has been found difficult to open the dispensing opening or dispensing spout in such fashion that the filling spout can be inserted, since the sheet material walls often tend to stick together.
A flexible plastic bag is known from US-A-40-78 717 which was produced from a sheet material tube. Grip aids are impressed in the sidwalls of the folded tube to make a manual unfolding of the bag possible. However, these grip aids do not allow the putting on of suction means.
A bag consisting mainly of cardboard is known from US-A-42 61 253. The impressing lines in the sidewalls of the bag and at a folding edge serve as joints, about which an unfolding of the sidewalls of the bags in prismatic form becomes possible upon the exertion of pressure on the opposite side edges.